title: New regression formulas for sonographic weight estimation within 10, 7, and 3 days of delivery.
abstract: OBJECTIVE
  The purpose of this study was to develop new regression formulas based on large numbers of sonographic examinations performed within 10, 7, and 3 days of delivery.
  
  
  METHODS
  Sonographic fetal biometric measurements and delivery ward data for an unselected population were analyzed. Multivariate linear regression models were fitted to the sonographic data to predict the actual birth weight (BW) within 10, 7, and 3 days.
  
  
  RESULTS
  The analyses included 6289, 5449, and 4007 patients who underwent sonographic examinations within 10, 7, and 3 days of delivery, respectively. All models yielded very high correlation coefficients (r = 0.927-0.958; R(2) = 0.859-0.918), low mean deviations between the calculated and actual BWs (6.4%-6.6% +/- 1 SD of 5.5%-5.9%), and high percentages of the calculated BW within 10% of the actual BW (78.5%-80.4%). Estimated fetal weight analyses made within 3 days of delivery yielded slightly better results than within 7 and 10 days.
  
  
  CONCLUSIONS
  The new regression formulas yielded overall similar results, with a small advantage for estimates calculated within 3 days of delivery. Further prospective studies are needed to compare the accuracy of these formulas with those used to date.
authors.affiliation: Department of Obstetrics and Gynecology, Helen Schneider's Hospital for Women, Rabin Medical Center, 49100 Petach Tikva, Israel. yudavi@inter.net.il
authors.forename: Avi
authors.initials: A
authors.lastname: Ben-Haroush
authors.forename: Nir
authors.initials: N
authors.lastname: Melamed
authors.forename: Reuven
authors.initials: R
authors.lastname: Mashiach
authors.forename: Israel
authors.initials: I
authors.lastname: Meizner
authors.forename: Yariv
authors.initials: Y
authors.lastname: Yogev
mesh_terms: D001699:Biometry / Q000379:methods*; D001724:Birth Weight; D003627:Data Interpretation, Statistical; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007231:Infant, Newborn; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*